William c



ct. 14 i924.

W. C. CARR INDUSTRIAL TRUCK Filed Feb. 9 -1922 2 shems-snee 2 Patented Oct. 14, 1924.

UNITED STATES PATENT OFFICE.

WILLIAM C. CARR, 0F BUFFALO, NEW YORK, ASSIGNOR TO THE. AUTOMATIC '.IRANSn POBTATION COMPANY, OF BUFFALO, NEW YORK, A CORPORATION OF ARIZONA.

INDUSTRIAL TRUCK.

Application filed February 9, 1922.

To .all whom .it may concer/a.'

Be it known that I, VILLiAM C. Gann, ka citizen of the United States, residing at Buffalo, in the county of Erie and State of New York, have invented certain new and useful Improvements in Industrial Trucks, of which the following is a specification.

This invention relates to improvements in motor-driven industrial trucks of the type wherein a lifting platform is provided for picking `up lor depositing the loaded skid.

The invention relates particularly to improvements in the mechanism for operating the lifting platform. The principal object is to provide mechanism which shall be durable, simple in structure and compact in organization, and which shall secure the highest degree of efficiency .in the operations of raising and lowering said platform, such `:etliciency having a. three-fold aspect, namely speed of operation consistent with safe hanidling of the objects to be moved, economy of power, and extent of lift. A further object is to make simple and effective provision for maintaining the platform stable in a horizontal plane, regardless of the weight .of .any loads upon its projecting end portions.

With the above objects .in view the invention consists generally in novel details of structure and organization of the operating gearing for the lifting platform and in the operative connections between said gea-ring and said platform.

An .embodiment of the invention is illustrated in the accompanying drawings, wherein:

Figure l is a partial side elevation of a truck in which the features of improvement are incorporated, the platform being in its lower position.

Figure 2 is a partial elevation of the opposite side `of the truck, the platform being in its elevated position.

Figure 3 is a view, partly in side elevation and ypartly in longitudinal section, showing details of the worm gearing which is directly driven by the shaft of the operating motor.

Serial No. 535,245.

Figure 4 is a cross section on the .line 4% of Figure 3.

Figure 5 is a longitudinal section .on the line 5-5 of Figure 4f.

Figure 6 is a sectional view on .the line 6 6 of Figure 1.

The features of improvement are ,applicable to la truck of the general type shown in my prior Patent, No. 1,248,075 of November 27, 1917, and which includes a 'frame 1 su ported by front and rear wheels whereof on y the rear wheels 2 are shown), a propelling :motor 3 connected by suitable gearing 4 to the rear wheels, a lifting platform 5, a motor 6 for the operation of said platform, and storage batteries 7 as the source `of `current for the `operation of the motors 3 and 6. The batteries 7 maybe conveniently supported above the .motors and `their associated gear trains and the platform 5 is, of course, arranged in front of the motors and above the frame 1. The platform 5 is directed rearward and upward or forward and downward by suitable means, preferably of the constructionshown .in my said prior pat- .ent and consisting of raising blocks 8 secured to the under face `of the platform and having inclined bearing edges 9 'terminating at their lower vends in flat, horizontal bearing surfaces 1Q, said blocks co-operating with rollers 11 having suitable fixed bearings in parts of the frame 1.

Where, as preferred, .the movements of the platform 5 are directed by the co-operating blocks 8 and rollers '11, said platform is operatively connected to a transverse shaft 12, the connections including a crank arm 13 on said shaft and a suitable linkaffe between said crank arm and the platform. 9re'ferably, however, and in accordance with certain specific features of the invention, the connecting linkage is of the construction shown, that is to say it includes a link 14 pivoted `to a bracket 15 at the front end of the platform and connected `by another link 16 to the crank arm 13, and a radius arm 17 having a fixed pivot 18 on some part of the `framing or other stationary part and also connected to the .mutual pivot '19 of the links 14 and 16, the function of the arm 17 being to prevent the platform from tipping in consequence of a load on either end por tion, i. e., portion projecting beyond the rollers 11.

According to the invention the motor 6 for the operation of the lifting platform has its axis at an angle to the axis of the crank arm 13, and its sha-ft drives the worm wheel 20, which is preferably coaxial with said crank arm and is connected thereto by spur reduction gearing. The shaft 21 of the motor 6 is connected by a suitable coupling 22 to a coaxial shaft 23 which carries a worm 24 in mesh with the worm wheel 20, the shaft 23 and worm wheel 2O being enclosed in a suitable casing 25 and `having suitable anti-friction bearings. The worm wheel 2O is mounted upon a transverse shaft. 26 which carries the initial element 27 of the spur gear reduction train.

In the construction preferred the shaft 26 is also utilized as the support for the final element 28 of the reduction train, the hub of the gear 28 being extended to provide the shaft 12 above mentioned and upon which the crank arm 13 is keyed. The reducing spur gear is completed by elements 29 and 30 mounted on a counter-shaft 31. The gear 27 is small and meshes with the gear 29 which is large and the gear 30 which is small meshes with the gear 28 which is large and thereby drives the shaft 12 from the shaft 31. The spur reduction gear comprising the elements described is enclosed in a suitable casing 32.

The coupling 22 is preferably fashioned to provide a brake drum for co-operation with brake elements 35 which are movably mounted upon suitable supports and are pressed into engagement with said drum by actuating springs 36. The brake elements 35 are disengaged from the drum by a cam 37 which Works in opposition to the springs 36 and is mounted on a rock shaft 38 having an arm which is connected by a link 39 to the core of a solenoid 40. When the cur` rent is on for the operation of the motor 6 the solenoid is energized and through the connections described moves the cam 37 to a position in which it holds the brake elements 35 disengaged. When the current is cut off the springs 36 effect the engagement of the elements 35 with the brake drum and the rotation of the motor is thereby arrested.

The means for starting and stopping the motor 6 form no part of the present invention and the following elements of such means are enumerated merely for the purpose of identification. The controlling switch is enclosed in a casing 41 and is operated by a vertically movable rod 42 suitably connected to a controlling handle 43 at the rear of the truck. rIhe connections between the handle 43 and the rod 42 include a lever 44 having an extension portion 45 by means of which the switch may be operated automatically in connection with the raising and lowering of the platform 5, the extension portion being directly engaged by the front end of the platform when the latter is raised and being engaged and operated by a hook connection 46 when the platform is lowered. As to these features a companioln application Serial No. 535,246 has been fi ed.

The gearing for the operation of the platform 5 operates with more rapidity and with less resistance to the motor than the gearing shown in my said prior Patent No. 1,248,075 while at the same time effecting a lift of the platform 5 through a greater vertical extent. I-Ience greater economy both in power consumption and in the time required for the use of the truck is effected while the increase of the vertical movement of the platform 5 will greatly facilitate the use of the truck under certain conditions more or less frequently encountered in industrial plants, The present gearing has the same advantage as the gearing shown in my patent referred to, namely the platform 5 is raised by the movement of the crank 13 through half a revolution and is lowered during the movement of the crank through the remaining half revolution whereby it is unnecessary to reverse the motor 6 in raising and lowering the platform. A further advantage of the gearing herein described and in accordance with the features of the invention is that the actual descent of the platform may be accomplished under the weight of the load and does not require to be accomplished under power. Thus in effecting the lowering of the platform in order to deposit the loaded skid upon the floor the motor is operated to move the platform horizontally forward sufficiently to disengage the bearing surfaces 10 from the rollers 11, afterfwhich the current may be cut off and the platform 5v may be permitted to descend under the weight of the load, that is to say to coast to its lower position.

Having fully described my invention, I claim:

l. In an industrial truck, the combination of a lifting platform, an operating crank therefor, link connections between said platform and crank, a supporting frame, rollers and co-operating cam elements mounted on said frame and platform respectively, and constituting means for raising or lowering said platform in accordance with the direction of the movements effected by said link connections and a radius arm pivotally mounted at a fixed point and joined to said link connections to prevent the platform, as elevated, tilting in either direction in consequence of a load borne on either end thereof.

2. In an industrial truck, the combination of a lifting platform, an operating crank therefor, link Connections between said platform and crank, a hollow transverse shaft upon which the Crank is mounted, an operu l ating motor having its axis at an angle to said shaft, a worm wheel, a transverse Shaft carrying the Worm Wheel and proj eoting into Said hollow shaft, a shaft coaxial With and driven by said motor and having a Worm for engagement with said Worm Wheel and a 10 spur gear reduction train interposed lietween the Coaxial Worm Wheel-carrying and Crank-carrying shafts.

'In testimony whereof I aix my signature WILLIAM C. CARR. 

